Gyro pilot



y 4, 1954 T. o. SUMMERS, JR 4 GYRO PILOT 5 Sheets-Sheet 1 Filed June 28,1950 I v "i INVENTOR.

WIUMHS #7- SUMMEE$,JE.

PTTOQA/EV May 4, 1954 T. o. SUMMERS, JR

GYRO PILOT 5 Sheets-Sheet 2 Filed June 28 1950 I INVENTOR. r m/4s 0.SUMMEPS,JB.

BY Z. A prmewa May 4, 1954 T. o. SUMMERS, JR

GYRO PILOT 5 Sheets-Sheet 3 Filed June 28. 1950 INVENTOR. mow/vs a.sun/mega May 4, 1954 'r. o. SUMMERS, JR 2,577,514

I GYRO PILOT Filed June 28, 1950 5 Sheets-Sheet 4 IN V EN TOR. man/2s a.SUM/H623, .12.

P. Mm,

May 4, 1954 T. o. SUMMERS, JR

GYRO PILOT 5 Sheets- Sheet 5 Filed June 28 1950 INVENTOR. 77/06/95 0.SUMM25',JR. BY [6 Patented May 4, 1954 hATENT OFFICE GYRO PILOT Thomas0. Summers, Jr., ShermanOak's, Calif.

Application June 28, 1950, Serial No. 170,720

14 Claimsr (Cl. 24479)" This'invention relates 'to' a novel gyro-pilot,and more particularly, to'an instrument which is capable of accuratelycontrolling the-rate'of turn of an aircraft While in flight. In order'toobtain the desiredresults; a gyro having-an inner out-3' gircbal ismounted-*so "that its spin axis normally lies in 'the vertical fore andaft plane of symmetry of the aircraft, with its spin tilted; forward"from theverti'ca'l axis of the aircraft. This tiltingoi the gyroprovides-av 111" he of sensing either yaw or roll of the airci a givendirection. A novel means of" processing and simultaneously case erectingthe gyro provided, whereby the gyro will be precessed at a constantrateso as to control the rate of turn of the aircraft. The precessing meanscan also be used to cage the gyro before night 01' under normal flightconditions, and therefore provide a single efii'cient means for bothcaging the gyro andprecessing the gyro to change the course of theaircraft.

revious gyro pilotshaveutilized a reversible torque motor about onegimbal axis of the gyro for processing thegyro inorder to control therate of turn of the aircraft-either to the right or left. When such atorque motor is used, an additional torque motor is required about-thetl r axis of the gyro so that the gyro can erected. It is quite obviousthat the use of a torque motor about the inner gimbal has thedisadvantage-that electrical power must be supplied to the torque motorthrough outer gyro gimbal, which results in consider-- g diiiiculty.Further, gyros equipped to" motors are bulky in design and very sive tomanufacture, and these factors become increasingly important whenaircraft are but for a single flight.

refore object of this invention to s a gyro pilot .9. novel processingmeans which is simple and compact in formand which an be mountedindependently of the gyro gimbal is also an object of the-invention asingle precessing means which can to easily and efdciently case erectthe e pr cessing the-gyro at a constant rate turning of the aircraft.urther object of this invention is to provide: pie and eirectivefollowup system and-one" .1 the rate of turn-of: an aircraft infleitheriwill be controll'edbythe rate of ten of the gyro as determined by theprocessing Itis also anobjeot -of 'this invention that the follow-upsystemhbe held to a craft about: the :desired" turning" path;

A. still further object of the invention is to provide a novelmountingand positioning arrangement forthe gyro, so that the gyro is sensitiveto either yawing or rolling of the aircraft in a given direction. Alsoincluded with the other objects of the invention is the novel electricalcircuit for transmitting electrical signals undercontrol of the gyro tothe proper control surfaces of the aircraft."

These and other objects of the invention, not enumerated aboveywillbeclearly set forth in the following description and in the drawings inwhich Fig, 1 is a side- View in elevation of the gyro pilot casingrigidly mounted to the aircraft structure 2 is a top plan view of thegyro pilot illustrated in Fig. 1.

3 is a vertical section view taken along line 3-'-3 of Fig. 2, showingthe gyro assembly in side elevation;

Fig. is a partial section view taken along line il of Fig.3,illustrating portions of the wiring circuit for the gyro motor.

Fig." 5 isapartialsectional-view along line 5-5 of Fig. 3, showingthe-processor assembly in cross section;

6 is a sectional'view of the gyro pilot housing along line 6-4; of Fig.3, showing the pickoliessembly in end elevation.

Jig. 7 is a sectionalview of the gyro pilot housing along-'1ine-'ll 'ofFig.- 3, showingthe electrical contact plates in' end elevation.

Fig. 8 is an end eleva'tional view of the electrical contact disk whichcomprises a part of the piclioff assembly.

Fig. 9 is a sectional view of the electrical contaot disl'etaken alongline 99 of Fig. 8.

1C is a view of the electrical wiring diagram utilizedforobtaining andtransmitting electrical signals to the aircraft control surfaces.

Thcembodiment' of the present invention, which hasbeen chosen forillustraticn and descriptiongcomprises a divided casing i mounted onsupport 2, which is a rigid part-of the aircraft with which the gyropilot is to be used. Casing extensions 3 and 4 respectively'enclosc thepre cessor assembl'y and pickoff assembly, which will later bedescribed.Cover plate 5 is held to casing extensions by -mea'ns ofscrews 6, whilecover plate 7 is secured? to casing extension 4 by screws 23. Ihecasingextension 9 housesthe electrical contac't 'box. th'roughiwhichpower is supplied to the-gyro 'motor and to the pich'off assembly. Coverpla teit! is secured to casing extension 5 by'screw's*l'l;-- A flexiblerubber gasket-Ill is posi- 3 tion d between casing extensions 3, 4 and 9and their respective cover plates in order to provide a dustproof sealfor the interior of the gyro pilot casing.

Referring to Fig. 3, a gyro having a two gimb-a support is showngenerally at 33. The cuts giinbal ring it is pivotally unted at one emby shaft it, which is suppoi ted by casing l and screw threaded to thecasing to provide for position adjustment. Nut 58 serves to loci: shaftto in any selected position. Two bearing races contain ball bearings El,which rotatively support giinbal ring 1-: upon shaft A similarsupporting structure is provided for the opposite end of ring i4,wherein shaft 58 is supported by extension l8 of easing i. Shaft 23 isscrew threaded to the extension it and contains a slot 26 for adjustingthe position of the shaft. Ball bearings 2! with associated races serveto rotat- The i and 28 (see Fig. s).

- and 25 serve to mount inner giinbal ring 2.. for rotation in shafts 23and 24 respectively. axis of the inner gimoal ring is therefore dispperpendicular to the axis of the outer gimbal ring. ihe gyro rotor andmotor (not shown) are mounted within inner gimbal ring 2.., with thespin axis of the rotor position perpendicular to the of the innergiinbal ring.

As previously noted, the spin axis of the gyro i3 is normally positionedin the vertical fore and aft plane of the aircraft with the upperportion of the axis tilted forward l5 degrees. The direction of forwardmovement of the aircraft along the fore and aft axis i indicated by thearrow in Fig. 3. Due to the inclined position of the gyro, it issensitive to both yaw and roll of the aircraft. With the gyro in thisposition, when the aircraft rolls and/or yaws to the left, it moves tothe left with respect to the outer gimbal, and when the aircraft rollsand/0r yaws to the right, it moves to the right with respect to theouter gimbal. The gyro therefore affords an instrument for accu-- ratelysensing the change in direction of the aircraft.

The connector 2'1 is provided with eight pins (only four of which areshown) for supplying electrical power and electrical signals to the gyropilot. Pin 22: is a 24 volt D. C. supply for driving the electrical gyromotor and for energizing the pickoff assembly and the processorassembly. Connected to pin or terminal 23 are three spaced contactplates mounted on an insulating member 32, which is ri idly held tocasing extension l9 by means of screws 33 (see Fig. '7). The pin orterminal 3 of connector 2'. leads to ground, and is connected to contactplate 35 mounted upon insulatin member 32. The outer gimbal ring of thegyro carries control arm which moves with the ring i4, and attached toarm 35 by screws 3? is an insulating member 33. The member carries fourspaced contact plates 3%], to, M, 5-2, which make sprin contact withplates 35, 3!, 35, since all of these plates are of material which canbe sli htly deformed to secure constant contact. The pairs of contactplates 3|, 39 and to, supply electrical current to the pickoff assemblyin a manner presently to be described. The pair of contact plates 22, 4!supply power to the gyro motor in order to rotate the gyro wheel uponits spin axis. It is readily apparent that the contact plates provide asimple J in which insulated ring Si is contained.

means for maintaining an electrical circuit, even though member 32 movesrelative to member 38. Connected to contact plate 4| (wiring not shown)is the arm 43 which rests on insulated plate and which is attached toouter gimbal ring M by means of insulated screws 45 (se Fig. 4). The arm43 bears upon one end of a silver pin 43 which extends through thecenter of shaft 24. An arm 41 is mounted upon gimbal ring 22 byinsulated plate 48 and insulated screws 49. The arm 47 contacts theother end of pin t5 and is also connected to the 24 volt D. C. motorwhich drives the gyro wheel at constant speed. The ground connection forthe gyro motor is connected (by circuit not shown) to a silver pin 53,which extends through the center of shaft 23. Arm 51, mounted byinsulated plate 52 and insulated screws 53, connects pin 52 with contactplate 42, which is in turn connected to ground through contact plate 35and pin in connector 27. By means of the circuit which has beendescribed, it is possible to supply electrical current to the yro motoreven though the motor is supported by the inner giinbal, which has twodegrees of freedom relative to the casing l.

Processor assembly The processor assembly contained in casin extension 3will now be described. An outer sleeve 5 is screw threaded foradjustment to extension 3 and surrounds an electrical solenoid coil Aninner cylindrical member 56 is positionez within coil and is providedwith an axial opening for receivin the processor 5'7. The coil isretained in position at one end by llllg a lien is secured by the peenedend 53 to member The opposite end of the coil 55 is retained by ringhaving a pressed fit with s eeve 54. Ring 33 has a shoulder whichprovides a reduced bore A slip ring $2 is separated by insulated washer63 from pressed ring and cylindrical member 55. The conducting rivets64, extending through slip ring insulated washer 53 and insulated rinSi, serve as a means for retaining slip ring 62 in position and providean electrical circuit between coil 55 and slip ring :32. An enlargedbore in one end of member 56 contains aspri a 65, which constantly bearsagainst the armatuie G's attached to one end of processor 51. Anextension 51 on the other end or" member 58 serves as a stop for theenlarged head of precessor 57 in order to prevent armature (it fromstriking cover plate when precessor 5'1 is moved by the action of spring85.

The enlarged head 86 of the processor is composed of a frictionalmaterial has a c cave surface for contacting the gyro dome This gyrodome is directly connected to the spi axis of the gyro and rotates withthe gyro rotor. The action of the precessor 5! upon the gyro when theprocessor head is in contact with dome 69 will now be explained. It iswell known that a force applied about one axis of a gyro will cause thegyro to process about an axis at right angles to the first axis. Assuminthat the p 'ecessor head 58 contacts dome 69 at some position on thedome which does not lie along the spin axis of the gyro rotor, atangential frictional force will then be applied to the dome surface,since the dome 69 is rotating. This frictional force will be in adirection which is at right angles to the direction from which theprecessor head 68 is displaced from the spin axis and will thereforecause the gyro to precess at ri ht angles to the frictional iorce'directi'onand" toward the pro cessor head 58; Of co'u'rse; ifthepre'cessor-head- 68 contacts dome BS at 'a position-directly alongthe spin axis; as"shown-in-' Fig 5, no effective force will bedeveloped,- and no'precessionwill takeplace. Ittherefore becomesapparent that when the precessordsdisplaced fromthe spin axis, the gyrowill continuouslyprecess until" the spin axis is broughtdi'rectlyunder--the"processor head 6 Another principal well known concerning gyros isthat the rate of precessiorri's proportionalto the magnitude of the'torqueapplied to the yroaxes. The magnitude of the torque appli'ed aboutthe gyro axes byprecess or hea'd 68*wil-l be the product of thefrictional 'force'des'cribed above, and the perpendicular distance ofthisiorce from a plane common to both gimbalaxest The 'preccssorassembly of this inv'entionis soflesigned that a very nearly constantfrictional force will be developed on the dome 69; while the processorEl is in operation, regardless of the position 01' the processor head68' relative to thespin axis. Also, due to the very slight curvature ofthe demo to in the proximity of" the spin 'axis, the precessor head Gilcan move some distance away from the spin axis andstill'remain'approximately tion or the majorgimbal axis, a torque willbe developed about the major axis and cause the gyro to process at aconstant rate about the minor gimhal axis in the direction. ofdisplacement of the processor head. By moving the processor head in thedirection of the minor'gimbal axis, a torque will be developed aboutthis axis and cause the gyro to process about the major gimbal at aconstant rate, and in the direction of the precessor head. If the head68 is displaced in any other direction, the frictional force on dome be?will be resolved and. result in torques being applied about both gimbalaxes to cause the gyro to precess at the same constant rate toward thehead 88.

Dueto the action'of theprecessor 51; it is useful in the gyro pilot ofthis invention for several purposes. Priorto take-off, the processor canbe used to cage the gyro, and for this purpose it is only necessary toenergize solenoid 55 so that processor head 68 contacts dome 69. Thegyro will then process until thespin axis is in line with the processorhead, as has been previously explained. Also, the precessor can be usedto develop a constant rate of'precession to maintain a constant rate ofturn,'as will be presently explained in connectionwith the descriptionof the pickoff assembly.

Piclcofi assembly 36 by screws '52. The plate! I is perpendicular to themajor axis of the gyro; A'circular electrical contact disk is positionedon plate! I" so that its center lies along the 'major a'xis of the gyro,and

the disk is composed ofari upper'sectionltand' a lower section 14, whichare attached by -rivets 151:0 plate H. by the space 16 andbyfthe'in'sulated wedges H and it, so that electrical current cannotflow from one disk to thebthe'rf' As shown in Figs. 8 and 9, the edgesof the disk sections are tapered to receive the taperededges-otthewedges when they are forced between thesections- From themanner in which the circular sections l3, 14 are mounted and positioned,itis obvious that the section will revolve'about the center of thecontact disk as the gyro precesses about its major axis.

An insulated plate 19 is attached by screws 83 to-rods lit which arerigidly secured to casing extension is so that the plate 19 will movewith the casing I. Three electrical contact arms 32, 83, 84 carryingcontact points 85, 86, 81 respectively are attached tomembers 88, whichare held to plate is by screws 89. Brackets 95 on members $8 aresupplied with screws 9| which bear against the cont ct arms to provide ameans of main taining the pressure of the contact points against thesections or" the contact disk. Under normal level flight conditions,contact point 87 rides upon wedge ll, while contact points 85 and 85 arepositioned respectively above and below wedge and in contact with disksections 14 and it respectively. However, if the aircraft rolls and/oryaws to the right, contact point 85 will approach wedge and if theaircraft rolls and/ or yaws to the left, contact point 86 will approachwedge "58. The use of the contact disk sections, and of the contactpoints will be presently explained in connection with the description ofthe control circuit for the gyro pilot.

Control circuit The control circuit is shown in Fig. 10, and thepositive side of the 24: volt D. C. supply is indicated at terminal 28.The electric motor 92 for the gyro is connected to ground at terminal 32. The line 93 constantly supplies a voltage to disk section "it throughline 54, and to disk section l3 through line so. The lines 96, Q7, 98connect contact points 85', 86, Site negative terminals 8!}, Hit, it)!respectively. Also, connected between line 93 and terminal 101- is theline it? containing the relay I03, which opens normally closed contactarm. 104 when it is energized. When contact 884 is. closed, it isconnected to line 83, and electrical current will flow through line W5and solenoid coil .55- to ground, and thereby cause the processor head88" to contact the dome 69. Line m5 is connected topositive terminaltel" so that current will not flow from line we to line 38.

The line supplying voltage to disksection 73 contains a relay N18 forcontrolling contact arm me, which is connected to ground and normallyopen. When arm [its is closed by relay lfiii, arm E55; connects positiveterminal l lil'to ground through line Hi. Also, line 911 contains arelay H2 which controls contact arm H 3; which is connected to groundand normally open. When arm H3 is closed by relay H2, the arm H3 con--nects positive terminal H4 to groundv through line H5. The positiveterminals. 1 ill and H l are connected to a servo control unit H6" whichis adapted to actuate the ailerons H8 in. one direction or the other,depending upon whichof the terminals is sending'the' signal. When it isdesired to maintain straight'fiight ofthe aircraft,

a negative signal is"applie'd to terminal IN" The disk sections areseparated through pivoted switch arm H. For a left turn, terminal it: iis disconnected and a negative signal is applied to terminal I throughswitch arm ii. For a right turn, a negative signal is applied toterminal 88 and terminal [BI is disconnected.

Gyro pilot operation The operation of the gyro pilot will now beexplained. Prior to iiight, and while the aircraft is level, it issometimes necessary to cage the gyro wheel so that the spin axis will bepositioned for proper operation of the instrument. For this purpose, itis onl necessary to apply a positive signal to terminal lcl while anegative signal is applied to terminal till. The contact arm Hi4 will beopen, and coil 55 will be energized so that precessor head 68 willcontact dome 6:) and precess the gyro into its proper position. Thecaging of the gyro can also be accomplished by giving either a right orleft hand signal, in which case terminal iti is tie-energized andcontact l is closed. Current will then be supplied through coil fromline 93, and the precessor head will be moved to cage the gyro.

As the aircraft takes ofi, only terminal 5 i receiving a signal, andcontact $5 is open 0 that the precessor 5? is inactive. The contactpoint 8i is therefore energized, and as as the aircraft is not turningto ri ht or left, point 8'! remains on insulated wedge i? (see Fig. 6).However, if the aircraft starts to turn to the left, point Bl contactsdisk section it allows current to flow through line so that relay itswill close contact arm Hi9. Teriinal ill; will therefore be energizedand the aileron servo will be actuated to move the control surface tobring the aircraft hack to normal straight night. If, in returning tostraight flight, the aircraft overshoots and banks to the right, contactpoint 8'! will engage disk section '14, which will result in currentflowing in line 95. Relay H2 will close contact arm H3 and terminal iiiwill be energized and the aileron servo will be actuated to bring theaircraft back to straight flight. Since point all is directly connectedto the aircraft, it will move relative to disl: sections iv and it whichare he d stationary in space by the gyro, since the processor 5'. is notin contact with the gyro dome. If the aircraft starts to turn to theright, point 8! will contact disk M and line HE will energize terminal EM to bring the aircraft back to straight flight. Therefore, contactpoint 81 provides means of normally guiding an aircraft straight on itscourse.

Assume that when the gyro is caged prior to flight, the aircraft istipped to one side or the other. The gyro would then assume a positionto maintain the aircraft in the rolled position that it had at the timethe gyro was caged. in other words, the gyro would not be in a positionto maintain level flight. As the aircraft takes off, it would thereforestart to turn, since the wings not level and the gyro is tipped.However, the gyro will sense the turning or yawing or" the aircraftwhich results from its rolled position, and point 8? will move off ofinsulated wedge ll. This will result in the servo moving the ail rons insuch a way as to stop the turning of the airplane. This is one advantageof having a tilted gyro which is sensitive to both yaw and roll aroundthe same axis, as has been previously describes. The point 8'! willcontinue to actuate the servo until the aircraft has leveled off and isflying a straight course. A straight course can only result if the minoraxis of the gyro is horizontal,

otherwise point 81 will try to roll the aircraft, during which time theaircraft will be turning. After the aircraft has turned enough to bringthe minor axis of the gyro into horizontal position for level flight,the aircraft will have leveled oil and the gyro will then correct anyroll which would tend to make the aircraft turn. It is thereforeapparent that the aircraft will level of; in straight flight in aslightly difierent direction from which it is headed if the aircraft istilted when taking off.

If, while the aircraft is flying straight, it is de sired to turn theaircraft to the left at a constant rate, a negative signal will beapplied to terminal E00. Terminal i0! thereby becomes neutral, causingcontact arm 104 to close and coil 55 to move precessor head 58 againstdome '69. Contact point 88 is in contact with disk section '2 whichallows current to energize relay ifiil to close contact arm I09. Theside or" the aileron servo connected to terminal H0 will then move theaileron in such a way as to cause a left turn. Once the control surfaceis moved from neutral position, the rate of turn will continuouslyincrease until the surface is moved bacl; to neutral position, at whichtime the rate of turn will tend to become constant. As the aileron isactuated for a left turn, the contact point 88 will approach insulatedwedge 78 at an increasing rate, corresponding to the increasing rate ofturn of t' aircraft. At the same time, processor head will move awayfrom the spin axis of the gyro and cause the gyro to precess at aconstant rate in the same direction as the point 88 is moving. Thecontact point 86 will therefore catch up to the insulated wedge '18,which is turning at t same constant rate as the gyro. During the tii ccontact point 35 is over insulated wedge 78, the servo will not actuatethe ailerons, which will be allowed to streamline so that the rate of trn of the aircraft w l remain constant at the dash value. Therefore, aslong as the rate of turn or the aircraft remains the same as theprecession rate of the gyro, the aileron servo will ram 11 inactive, andallow the aileron to remain streamlined. If the rate of turn becomes toogreat, the contact point 86 will move into contact with (it 1. section74, which will result in the closing of contact arm H3, and also theactuation of the servo to roll the aircraft in a direction to decree therate of turn. When the rate of turn dro behind the pro-selected rate,contact point will again contact disk section 13, and cause the aileronto move so as to bring the rate of turn back to the selected rate. Eachtime the ailerons are moved to correct the rate of turn, the rollimparted. to the aircraft is in a direction to move the contact point 86toward the insulated wedge 16.

When it is desired to turn the aircraft to the right at a constant rate,a negative signal on terminal ill will be removed. The contact arm i l iwill close and allow solenoid 55 to move processor head 68 against dome69 so that t c gyro will be precessed at a constant rate, once the sad63 has moved away from the spin a: The contact point 85 in contact withdisk section 74 will start current flowing in relay I [2 to closecontact arm l 13 and actuate the side of the servo connecte to terminalH4. This will cause the aileron to move and start the aircraft turningto the right. The contact point 85 will approach the insulated wedge 18at an increasing rate, as long as the aileron is actuated. At the sametime, precessor head 58 will move to the right of the spin axis andstart thSg QKGOGSSIODyofythe gyro.

After the contact -point-BS-reaches the insulated wedge 18, itwillremain on-the wedge .aslong as the rateof turn of theaircraft is;the same as the rate of precession-of the gyro.- :During this time, theailerons of the aircraft will be streamlined, If the rate of =turnbecomes toofast, contact point 3; will contact disk section 13 and causethe ailerons-to ,be moved to decrease the rate of turn. When the rate ofturn istoo slow, the point 85 will again contact: disk section [4 andcause the ailerons to be ,moved to increase the rate of turn. If thegyro were not; processed, straight flight would result. However, byhaving the gyro process at aconstant rate, it can provide a referencepoint which will determine the desired rate of turn. Whilethe'gyroscope, is-ibeing pro- .cessed by processor head68 toeffect-either a right or left turn, it is important that thegyroscopicrotor casing be maintained in substantially a constant position withrespect to thegyro casing l, since otherwise the essential tilt attitudeof the spin axis would be lost, It will be seen that the gyroscopic spinaxisis maintained in sub stantially constant relationship with'casing lfor the reason that should the-spin axis become misaligned with the axisof processor head 68, an erecting frictional force will be developed toprocess the gyro directly back into t e. position where the spin axisand the precessorhead are i alignment.

The aircraft can be leveled off at any time by removing the right orleft turn signal and again applying a negativesig-nal to terminal NH. Atsuch a time, the aircraft will be rolled sothat contact point 3'! willbe incontact with either disk sectio M or disk.secti0n;-l3,:depending onwhether the aircraft isexecuting a right orleft turn. This is due to thefact that the aircraft moved relative tothe gyro by the distance betweenthe wedge 18 and either of .the contact points or 86. Since the gyrowill not be precessing after terminalylfli isgiven a negative si contactpoints! will immediately cause the aircraft to roll in adirectiontolevel-ofi and move contact point 8'! towardwedge 11. Atthistime, the minor axis of I the gyrowilLstill be tipped from thehorizontal, since the gyro has been processed from its originalposition. However, the gyro will sense that the aircraft is stillturning will cause theaircraft to level off at such time as it haschanged direction sufficiently to level off the minor axis of the gyro.

The gyro pilot, which hasbeen described, is ca able of controlling thedirectionof-an aircraft ng flight. It can be utilized to turn theaircraft at a constant rate in eitherdirection orto keep the aircraft ona straight path; The novel processing means and follow-up means, whichcomprise features of the gyro pilot, have been made simple and compactso that the weight of the gyro pilot is not excessive; and positiveoperation of, the invention isassured. Variousmodifications arecontemplated and obviously be resorted to by thoseskilled the artwithout from the spirit and scope of the invention, as hereinafterdefined by the. appended claims.

What is claimed is:

l. In a gyro pilot for controlling the direction .t of an aircraf, agyro responsive to both roll and yaw of the aircraft, first means forprecessing said gyro at a constant rate about its roll yaw axis, secondmeans attached to said gyro for movement therewith, third servo meansfor positioning said aircraftebout its roll taxis, means cooperatingwith said second means when said gyro is not being processed to controlsaid servo means and maintain the aircraft in straight flight, andfourth means cooperating with said second means during precession ofsaid gyro by said first means to control saidservo means and maintainthe rate of turn of the aircraft constant in either direction.

2. In a pilot for controlling the direction of flight of an aircraft, agyro responsive to both roll and yaw of aircraft, processing means forprecessing gyro at a constant rate, means connected to said gyro andproviding two separated sources of potential, a relay connected to eachsource of potential, said relays hein operative one at a time to controlthe direction of turn of the aircraft, first, second and third contactpoints arranged to be selectively supplied with a negative sign 1 eachof said contact points cooperating n said potential sources whenreceiving a negative signal, and thereby serving to energize one or theo her "said relays to control the flight direction of the aircraft saidfirst contact point adapted to receive a signal while processing meansis inactive to keep the aircraft straight, said second contact pointadapted to receive a signal to process the gyro and to maintain aconstant rate of turn in one direction and said third contact pointadapted to receive a signal to precess the gyro and to maintain aconstant rate of turn in the other dire"- tion.

3. In a gyro pilot for controlling the direction of fright of aircraft,a gyro responsive to both roll and yaw of the aircraft, a spherical domeattached to the rotor of said gyro, a processor operative to contactsaid dome for processing the gyro at a constant rate, a solenoid forcontrolling the position of said processor, a control member attached tosaid gyro and movable therewith, a first circuit for de-energizing saidsolenoid so that said gyro is free in space, a member in said firstcircuit cooperating with said control member to maintain the aircraft inlevel flight, a second circuit for-energizing said solenoid so as toprocess the gyro, a member in said second circuit cooperating with said4 control member to cause said aircraft to turn in one direction at aconstant rate, a third circuit for energizing said solenoid so as toprecess the gyro, a member in said third circuit cooperating with saidcontrol member to cause said aircraft to turn in the other direction ata constant rate.

4. In a gyro pilot for controlling the direction of flight of anaircraft, gyro responsive to both roll and yaw of said aircraft, aprecessormovable into contact with said gyro to process said gyro at aconstant rate, a control member attached to said gyro and comprisingfirst and second disk sections separated from one another by aninsulating member, a first circuit for supplying a potential to saidfirst disk section and containing a first relay which operates to movethe control surface of the aircraft in one direction, a second circuitfor supplying a potential to saidsecond disk section and containing asecond relay which operates to move said control surface of the aircraftin the other direction, a third circuit .containing third relay whichoperates tomove said processor away from said gyro sothatit .will notprecess said gyro, a first contact point in said third circuit normallyengaging said insulating member when receiving a straight fiightsignaland movable to contact-either saidfirst or second disk section toenergize either said first or second relay to correct for any roll ofsaid aircraft away from straight flight.

5. In the gyro pilot of claim 4, said first contact po nt being movableto contact said first disk ection and energize said first relay when theaircraft rolls to the right and movable to contact second disk sectionand energize said second relay when the aircraft rolls to the left.

6. In the gyro pilot of claim 4, a second contact point normallycontacting said first disk sec tion during straight flight andresponsive to a right turn signal to operate said first relay and causethe gyro to precess to the right, said contact point remainirr on saidinsulating member when the rate of turn to the right is equal to therate of precession of said gyro to the right and movable to contacteither disk section to operate either the first or second relay to maintain the desired rate of turn of the aircraft, a third contact pointnormally contactin said second disk section during level and. rcsponsiveto a left turn signal to operate said second relay cause the gyro toprocess to the left, third contact point remaining on said insulatingmember when rate turn to the left is equal to the rate of precession ofsaid gyro to the left and movable to contact either disk section tooperate either the st or second relay to maintain the desired of turn.

'7. In a gyro pilot for controlling the direction of flight of anaircraft, a gyro responsive to both roll and yaw of said aircraft, aprecessor movable into contact with said gyro to process said gyro at aconstant rate, a control member attached to said gyro and comprisingsecond disk sections separated from one another by an insulating member,a first circui for supplying a potential to said first disk section andcontaining a first relay which operates to move the control surface ofthe aircraft in one direction, a second circuit for supplying apotential to said second disk section containing a second relay whichoperates to move said control surface of the aircraft in the otherdirection, a first contact point normally contacting said first disksection during level flight and responsive to a right turn signal tooperate said first relay and cause the gyro to process to the right,said first contact point remain mg on said insulating memher when therate of turn to the 1 ht is equal to the rate of precession of said 1:10to the right and movable to contact either disk section to operateeither the first or second relay to maintain the desir d rate of turn ofthe aircraft, a second contact point normally contacting said seconddisk section during level flight and responsive to left turn signal tooperate said second relay and cause the gyro to precess to the left saidcontact point remaining on said insulating member when the rate of turnto the left is equal to the rate of precession of gyro to the left andmovable to contact either disk section to operate either the first orsecond relay to aintain the desired rate of turn.

8. In a gyro pilot for controlling the direction of flight of anaircraft, a gyro responsive to roll and yaw of the aircraft, servo meansfor positioning said aircraft about its roll axis, first means attachedto said gyro, second means attached to the aircraft and normallycooperating with the said first means to control said servo means andmaintain said aircraft in straight flight, a single precessor forselectively processing said gyro at aconstant rate in either directionCir ' be responsive to both roll and yaw of the about the roll-yaw axisof said gyro, and third means attached to the aircraft and cooperatingwith said first means during precessional movement of said gyro by saidprecessor for controlling said servo means and maintaining co1istantrate of turn of the aircraft in a direction corresponding to thedirection of precession of the gyro, said second means being inoperativeto maintain straight flight during operation of said precessor.

9. In a gyro pilot for controlling the direction of flight of anaircraft, a gyro responsive to the roll and yaw of the aircraft, servomeans for positioning said aircraft about its roll axis, means forprocessing said gyro at a constant rate about the roll-yaw axis of saidgyro, a contact list. comprising two sections separated from one anotherby insulating means and attached to the roll gimbal of said gyro, saiddisk sections being constantly connected to a potential source, a firstpickoff movable with the aircraft and cooperating with said insulatingmeans to con-- trol said servo means and maintain st1 flight when saidprecessing means is inoperative and a second pickoff movable with saidair and cooperating with said insulating means while said processingmeans is operative to control said servo means and cause said aircraftto turn a rate corresponding to the rate of procession of said gyro.

10. In a gyro pilot for controlling the direction of flight of anaircraft, a gyro universally sup ported by the aircraft and having itsspin inclined fore and aft in order for the gyro to craft, a singleprecessor for precessing said 1 at a constant rate in either directionabout its roll-yaw axis, control means attached to said gyro and movabletherewith, means selective to activate said precessor to process saidgyro in one direction about its roll-yaw axis, operative upon actuationof said last mentioned means to cooperate with said control me. to causesaid aircraft to move in said one direction at a constant rate equal tothe precession re e of said gyro, means selective to actuate saidprecessor to process said gyro in the opposite dicotion about itsroll-yaw axis and means operative upon actuation of said last mentionedmeans to cooperate with said control means to cause aircraft to move insaid opposite direction constant rate equal to the precession rate ofsaid gyro.

11. In a gyro pilot for controlling the direction of flight of anaircraft, a gyroscope having a gyro rotor mounted for universal movementa a spin axis, a pickoif means having one porattached to said gyroscopeand another por I on attached to said aircraft, said pickoif meanshaving a straight flight null position and turn null position spacedtherefrom by slight amount, a spherical surface mounted to rotate withsaid gyro rotor and a single precessor mounted by said aircraft inposition to cooperate with said surface and thereby precess said rotor,said precessor being inoperative and positioned in line with said spinaxis during straight i of said aircraft, and means for causing precessorto cooperate with said surface simultaneously changing the null positionor pickoif from its straight flight position to turn position, saidprecessor thereafter assur a position slightly displaced from said spinpositions to continually precess said gyro rotor at a constant rate.

12. In a gyro pilot for controlling the direction of flight of anaircraft, a gyroscope mounted for universal movement and having a spinaxis, a single precessor mounted by said aircraft for applying a forceto said gyroscope to cause said spin axis to move toward said precessor,a pickoif means including one portion attached to said gyroscope andanother portion attached to said aircraft, said pickoif means having astraight flight null position and a turn null position spaced slightlytherefrom, said precessor being inoperative to precess said gyro duringstraight flight when said straight flight null position is controllingand means for causing said turn null position to become controlling andsimultaneously causing said processor to apply a force to said gyroscopeat a position displaced from spin axis by a slight amount determined bythe distance between said null positions.

13. A gyroscopic controller comprising, a gyroscope having a gyro rotormounted for free universal movement relative to a stationary support, aspherical surface operatively connected with said gyroscope, a singlecontact element operatively connected with said stationary support forselective engagement with said spherical surface, a pickoif meansincluding one portion attached to said gyroscope and another portionattached to said support, means for changing the null position of saidpickoff by a small increment when it is desired to turn said aircraft,and means for causing said element to engage said spherical surface uponchange in the null position so that said processor Will be displacedfrom said spin axis by an amount corresponding to the increment changein the null position and thereafter continually precess said gyroscopeat a constant rate.

14. In a gyro pilot for controlling the direction of flight of anaircraft, a gyroscope means mounted for universal movement, pickoifmeans having one portion attached to said gyroscope means and anotherportion attached to said aircraft, means responsive to said pickoffmeans for controlling the direction of flight of said aircraft, meansfor turning said aircraft by changing the null position of said pickoifand means responsive to the actuation of said turning means forprocessing said gyroscope at a constant rate in order to maintain therate of turn constant.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 2,190,390 Thiry Feb. 13, 1940 2,280,116 Carlson Apr. 21, 19422,446,180 Haskins Aug. 3, 1948 2,493,015 Newton Jan. 3, 1950 2,513,120Turner June 27, 1950 2,559,298 Hayes July 3, 1951

